The present disclosure relates to developing devices and image forming apparatuses with the same and particularly relates to a mechanism for moving a developing roller into and out of contact with an image carrier.
Electrophotographic image forming apparatuses are provided with developing devices in which a developing roller supplies a developer to an electrostatic latent image formed on a photosensitive drum (image carrier) to generate a toner image. In such a developing device, in order to enable the supply of the developer, the developing roller is disposed close to the photosensitive drum to the point of almost making contact with the photosensitive drum. Meanwhile, in order to enable the removal of the developing device without damaging the photosensitive drum at the time of maintenance, the developing device is provided with a mechanism for moving the developing roller from the position close to the photosensitive drum to a position away from it.
For example, there is known an image forming apparatus which includes a developing roller transfer mechanism composed of: an arm member mounted to a developing roller for unitary rotation with the developing roller; and a shaft member disposed movably along an axial direction of the developing roller and allowing the unitary rotation of the arm member with the developing roller while moving in the axial direction. There is also known a developing roller transfer mechanism configured to smoothly slide the shaft member using a slide auxiliary member.